Manufacture and production of n-monoalkyl derivatives of aromatic compounds



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ARTHUR- LMWQIRTH, UT MANEHEST, ENGLAND.

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Ito Drawing.

To all whom it may concern:

Be it known that l, ARTHUR LAPWon'rir, a subject of the King of Great Britain and Ireland, and a resident of Manchester, in the county of Lancaster, England, have invented certain Improvements in the Manutacture and Production of N-Monoalkyl Derivatives of Aromatic Compounds, of which the following is a specification.

This invention relates to the manufacture and production of N-monoallryl derivatives of certain aromatic amino compounds.

The monoalkylation oi an amine by treatin its benzylidene compound with an alky iodide and hydrolysin the product thus obtained has been success ully achieved with bornylamine a derivative of camphor. The process failed, however, when applied to t-naphthylamine and phenylhydrazine.

We'have now discovered that the aldehyde derivatives ot (1) I p-substituted amines and their derivatives of the benzene, naphthalene or other aromatic series, or

(2) such other amines of these series and their derivatives which do not either as amines or as N-alkylamines react in the presence of acids With the required aldehydes in such a manner as to roduce amino derivatives of diarylmonoal 'lor of triarylinethanes, yield on treatment with alkylating agents, tor instance alkylusulphates and alkyl esters of benzene sulphonic acid, N:- monoalkyl substitution products. These compounds are decomposed on being hydroe lysed, the aldehyde being eliminated with formation of a salt of an N-monoalkyl derivative of the amine. The tree monoalkyl base can be obtained from the salt in the usual way.

The followin examples will serve as. illustrations of ow the invention may be Application filed .Fune to, with. fierial Ito. 3 1%.

is distilled withsteam. The benzylidene product is hydrolysed and the benzene and. benzaldehyde pass over with the steam. The remaining. clear aqueous solution is concentrated to a small bulk and the bases are liberated from their salts by the addition of sodium carbonate. They consist of a mixture of p-aminophenol (about 25-30%) and p-methylaminophenol (about 75%) and the p-methylarninophenol can be separated theretrom by any of the well-known methods, for instance, by treating the mixture, after the addition of hydrochloric acid, with sodium nitrate, separating the soluble diazo compound from the insoluble nitrosomethylamino-p-phenol by filtration and washing, and eliminating after thorough washing the nitroso group from the nitroso-- methylamino-p-phenol by treatment with tin and hydrochloric acid. Unly negligible quantities of the dialkyl base were found in the reaction product.

Ewample 2.

A. mixture of 20 parts of benzylidene-ptoluidine, 72 parts of benzene and 14 parts of dimethyl sulphate is boiled on the water- Example 3. 20 parts of the benzylidene derivative of I-bromo-Q-naphthylamine are dissolved in 50 parts of boiling benzene and 6.9 parts of dimethyl sulphate (freshly purified and discarried into effect, the parts being by weight. tilled) are added to the solution. The boil- Emample 1.

it mixture of 20 parts of benzylidene-pamidophenol and parts of benzene is boiled under a reflux condenser on the waterbath and 14:.5 parts of dimethyl sulphate (freshly purified and distilled) are then added thereto. The boiling is then continued for seven and a half hours, the mixture being well stirred. 14 parts of con centrated hydrochloric acid and a little water are thereupon added and the whole nitroso compound of l-bromo-Q-haphthyl- 1w 'ing isthen continued for 10 hours. After the subsequentaddition of hydrochloric acid and water, and distillation with stearmthe residual liquid is allowed to cool and is then made alkaline with sodium carbonate. The precipitated bases are it necessary, extracted with a solvent, e. g benzene or chloroform, and recoveredtrom the solution by removal of the solvent The residue is dissolved in excess ofhydrochloric acid and then treated in the usual Way with sodium nitrate. The

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amine separates in yellow crystals, melting after recrystallisation from petroleum at from 108110 C. The nitroso group is then removed by treatment with tin and hydrochloric acid and the hydrochloride oi 1-bromo-2-methylamino-naphthylene 1s obtained in crystals P. 179181 C.)

which are soluble in hydrochloric acid, but are largely dissociated by water. The free base is a low melting solid and tends to persist as a fluid at ordinary temperature. I do not limit myself to the examples glven and instead of the condensation product of benzaldehyde with the amines, condensation products of other aldehydes with amines can be used. The diluent benzene can be replaced by solvents of suitable character, for instance, toluene, xylene, nitrobenzene, etc. Furthermore, other processes may be employed for obtaining the pure N-monoal%lh body from the product of reaction.

at I claim as m invention, and desire to secure by Letters atent is 1. The process of'producing N monoalkyl derivatives of aromatic compounds which comprises boiling a condensation product of aromatic aldehydes with amines, with a solvent of the benzene series, then adding dimethyl sulphate and continuing the boiling, then addmg hydrochloric acid and water and distilling with steam to remove the benzene compounds.

2, The processof producing N monoalkyl derivatives of aromatic compounds which comprisesboiling a condensation product of aromatic alldehydes with amines, with a solvent of the benzene series, then adding dimethyl sulphate and continuing the boiling, then addin hydrochloric acid and water, distilling 'with steam to remove the benzene compounds, concentratin the remaining clear aqueous solution, an then liberating the bases with sodium carbonate.

3. The process of producing N monoalkyl derivatives of aromatic compounds which comprises boiling a mixture of 20 parts by weight of a condensation product of aromatic aldehydes with amines, and 72-100 parts by weight of a solvent of the benzene series, then addin dimethyl sulphate and boiling further, t en adding hydrochloric acid and water and distilling with steam to remove the benzene compounds.

4. The process of producing N monoalkyl derivatives of aromatic compounds which comprises boiling a mixture of 20 parts by wei ht of a condensation product of aromatlc aldehydes with amines, and 72-100 series, then adding 14 parts b parts by weight of a solvent of the benzene series, then adding 14 parts b weight of tilling with steam to remove the benzene compounds.

5. The process of producing N monoalkyl derivatives of aromatic compounds which comprises boiling a mixture of 20 parts by weight of a condensation product of aromatic aldehydes with amines, and 72400 parts by weight of a solvent of the benzene series,'then adding dimethyl sulphate and boiling further, then adding hydrochloric acid and water, distilling with steam to re move the benzene compounds concentrating the remaining clear aqueous solution, and then liberating the bases with sodium carbonate.

6. The process of producing N monoalkyl derivatives of aromatic compounds which comprises boiling a mixture of 20parts by weight of a condensation product of aromatic aldehydes with amines, and 72-100 parts by weight of a solvent of the benzene weight of dimethyl sulphate and boiling urther, then adding hydrochloric acid and water, distilling with steam to remove the benzene compounds concentrating the remaining clear aqueous solution,-'and then liberating the bases with sodium carbonate.

7. The process of producing N monoalkyl derivatives of aromatic compounds which comprises boiling a condensation product of aromatic aldeh des with amines, with a solvent of the enzene series, then adding dimethyl sul hate and continuing the boiling, then ad ing hydrochloric acid and water and distilling with steam to remove the benzene compounds, coolin the remaining solution and rendering al zaline with sodium carbonate to liberate the bases.

8. Theprocess of producing N monoalkyl derivatives of aromatic compounds which comprises boiling a condensation product of aromatic aldehydes and amines, with benzene, then adding dimethyl sulphate and continuing boiling for. at least one hour, then adding hydrochloric acid and water, and distilling with a current of stream to remove the benzene compounds and then liberating the bases by treating the solution with sodium carbonate.

In witness whereof I have hereunto set my hand.

ARTHUR LAPWORTH. 

